This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cytomegalovirus (CMV) is an important cause of illness, and even sometimes death, in infants, as well as children and adults whose immune systems are weak. Though there have been studies about CMV in both young and older females, in general, less is known about how adolescent males get CMV. The goals of this study are to identify different risks factors associated with getting CMV and how common the virus is in adolescent males. The aims of the study are broken up into three different phases. Phase I is to determine how common CMV is in adolescent males and to identify risk factors. Phase II is to study how many adolescent males get CMV over two years and to identify the risk factors. Finally, Phase III is to determine how much virus is in the blood, urine, and saliva of those adolescent boys who were infected with CMV during Phase II. In Phases I and II of the study, subjects will complete a questionnaire by computer, investigating possible risk factors for CMV, including, sexual practices, and household and environmental practices. In Phases I, II, and III, blood will be drawn to test for CMV;in Phases II and III, urine will be collected to test for CMV;finally, in Phase III, saliva will also be collected to test the amount CMV present in the samples. Knowledge gained by collecting data about how common CMV is in adolescent boys will lead to future studies about CMV vaccines.